Do you have to move the cursor, and move it backwards or just leave it where it is because if its on a space where it shows max vps and max money why would you move it?
The player can move the Workshop cursor, horizontally and/or vertically, a number of spaces equal to the total number of works he has in front of him.Upon rereading I think that you're asking if you must move the full amount or if you can move fewer spaces than that. It's somewhat ambiguous in the wording now that I look at it... but you may move the cursor up to a number of spaces equal to the number of works you have in front of you.
That's how it is implemented online at boiteajeux.net at least. And it wouldn't make much sense to be all or nothing. This is a bonus ability for having collected more paintings. It should be a benefit, not a restriction.